Endophytes: The Other Maize Genome

Abstract

Endophytes are microorganisms that live inside plants without causing disease. Maize endophytes collectively encode roughly twenty times as many genes as maize itself, giving the plant access to incredible genetic diversity. They can affect their host plant by altering growth, nutrient acquisition, disease resistance, insect resistance, and abiotic stress tolerance. Despite the richness of these communities, the rules that govern their assembly and their functions within the maize plant are complex and poorly understood. We outline what is known about maize endophytes, including which organisms are known to live inside maize, how they are transmitted, what genomic functions they encode, what effects they have on their host, and how they interact with each other and the maize plant. Many questions still remain about maize endophytes, including what makes a healthy endophyte community, how that community is assembled and develops, and how endophytes can be harnessed to improve agriculture.